ios uitextfield 和按钮转换出现/消失

Question

我有一个 ipad 应用程序，当用户执行一些操作时，uitextfields 和按钮会在视图中出现和消失 [工作正常]

[cancelBtn setHidden: true];
[lblOption setHidden:true];

问题是是否有某种方法可以在它们出现和消失时设置动画，例如按钮的过渡、透明 alpha，

非常感谢！

Answer 1

是的。例如：

[UIView animateWithDuration:1 animations:^{
    cancelBtn.alpha = 0;
}];

详情请见the View Programming Guide for iOS。

Answer 2

          [self.view addSubview:btn5];
//            




//            [[txt1 layer] setBorderWidth:2.5f];
//            [[txt1 layer ] setBorderColor:[UIColor blackColor].CGColor];
//            



            [self.view addSubview:txt1];

            txt2=[[UITextField alloc] initWithFrame:CGRectMake(20,150,180 ,35)];
            txt2.backgroundColor=[UIColor brownColor];
            txt2.borderStyle=UITextBorderStyleRoundedRect;
            txt2.textColor=[UIColor whiteColor];
            txt2.adjustsFontSizeToFitWidth=YES;

            txt2.backgroundColor=[UIColor clearColor];





//            [[txt2 layer] setBorderWidth:2.5f];
//            [[txt2 layer ] setBorderColor:[UIColor blackColor].CGColor];
//            

            [self.view addSubview:txt2];


            txt3.userInteractionEnabled=NO;


//            [btn2 setSelected:NO];
//           [btn3 setSelected:NO];
//            [btn4 setSelected:NO];
//            
            NSLog (@"Movie selected");

            break;

         case 2:

//            [btn2 setSelected:YES];
            txt3=[[UITextField alloc] initWithFrame:CGRectMake(20,110,180 ,35)];
            txt3.backgroundColor=[UIColor brownColor];
            txt3.borderStyle=UITextBorderStyleRoundedRect;
            txt3.textColor=[UIColor whiteColor];
            txt3.adjustsFontSizeToFitWidth=YES;


            [self.view addSubview:txt3];




            txt1.userInteractionEnabled=NO;
            txt2.userInteractionEnabled=NO;




//            
//            [btn1 setSelected:NO];
//            [btn3 setSelected:NO];
//            [btn4 setSelected:NO];

            NSLog (@"Play selected");

            break;

        case 3:

//            [btn3 setSelected:YES];
//            
//            
//            
//            [btn1 setSelected:NO];
//            [btn2 setSelected:NO];
//            [btn4 setSelected:NO];
//           
            NSLog (@"Events selected");

            break;

    default:

//            [btn4 setSelected:YES];
//            
//            [btn1 setSelected:NO];
//            [btn2 setSelected:NO];
//            [btn3 setSelected:NO];

            NSLog (@"Sports selected");




           break;
    }

}

-(IBAction)radioButton:(id)sender
{
    switch ([sender tag]) {
        case 0:
            [rbtn1 setSelected:YES];
            [rbtn2 setSelected:NO];

            NSLog(@"Movies Selected");

            break;
        case 1:
            [rbtn2 setSelected:YES];
            [rbtn1 setSelected:NO];
            NSLog(@"Cinemas Selected");




//            if ([rbtn1 isSelected]==YES) {
//                [rbtn1 setSelected:NO];
//                [rbtn2 setSelected:YES];
//            } else {
//                [rbtn1 setSelected:YES];
//                [rbtn2 setSelected:NO];
//            }
//            
//            break;
//            case 1:
//            if ([rbtn2 isSelected]==YES) {
//                [rbtn2 setSelected:NO];
//                [rbtn2 setSelected:YES];
//            } else {
//                [rbtn2 setSelected:YES];
//                [rbtn2 setSelected:NO];
//            }

        default:
            break;
    }


}